Abstract A new furan annelation by the palladium-catalyzed reaction of 2-alkynyl carbonates with β-keto esters is described. The reaction proceeds under mild neutral conditions and hence unstable 3-alkylidene-2, 3-dihydrofurans can be prepared in this way. Similarly, reaction of 2-(1-alkynyl) oxiranes with β-keto esters gives alkylidene furans.
